Walking beam transfer device



June 1964 E. UMBRICHT ETAL WALKING BEAM TRANSFER DEVICE 4 Sheets-Sheet 1Filed Aug. 21, 1962 EL W.L L 6w June 30, 1964 E. UMBRICHT ETAL 3,139,171

WALKING BEAM TRANSFER DEVICE Filed Aug. 21, 1962 4 Sheets-Sheet 2 BYW/Al/AM J? BURMA/V ATTOR/VIYS June 30, 1964 E. UMBRICHT ETAL 3,139,171

WALKING BEAM TRANSFER DEVICE Filed Aug. 21, 1962 4 Sheets-Sheet 3 M R gINVENTORS L 5 fM/L u/ws/e/ cw" Q W/LL/A/V J7 BURN/IN June 1964 E.UMBRICHT ETAL 3, 7

WALKING BEAM TRANSFER DEVICE Filed Aug. 21, 1962 4 Sheets-Sheet 4 INVENTORS 01/4 UM Iv/cr/r BY lV/ll/HM J BURMA/V QMZZ WVW" United StatesPatent 3,139,171 WALKING BEAM TRANSFER DEVICE Emil Urnhricht,Northviile, and William J. Burrnan, De-

troit, Mich, assignors to Ajem Laboratories, Inc., Livonia, Mich.

Filed Aug. 21, 1962, Ser. No. 218,358 12 Ciairns. (Cl. 198-20) Theinvention relates to transfer devices and more particularly to devicesadapted to transfer a plurality of articles from station to station insuccession along a path.

Heretofore, there has been need for a transfer device capable ofaccelerating from a start position first upward to pick up articles, andespecially heavy articles, e.g., engine blocks, and then forward, anddecelerating again to stop the forward motion, and finally setting thearticle down at a second location, in a very precise manner, e.g., onlocating pins engaging small holes in the article, which must not sulferdamage from inertial impacts. To this end it is important to have thevertical movement of lifting and setting down substantially free fromhorizontal components so that a given point on the article to betransferred will follow a rectilinear path accurately aligned with thelocating device.

It is, therefore, an object of the invention to provide a transferdevice having separate periods of vertical and horizontal movement. i

Another object of the invention is to provide a transfer device capableof smooth acceleration and deceleration, both vertical and horizontal,so as not to cause shock to the article or equipment.

Another object of the invention is to provide a transfer device capableof accelerating from a start positionto pick an article ofi from smalland fragile locating means and, subsequently to decelerate whilelowering the article in a precise manner at a second location onto smalland fragile locating means.

Another object of the invention is to provide a transfer device capableof positively holding articles throughout the sequence of its operation.

Another object of the invention is to provide a transferdevice'adaptable to operation to different elevations, and adaptable toa wide range of speeds.

A still further object of the invention is to provide a transfer devicewhich is dependable, rugged, compact, uncomplicated, and relativelyinexpensive involving no undue maintenance and service.

Other objects and a fuller understanding of the invention will appearfrom the following description and claims, taken in conjunction with theaccompanying drawings in which:

FIGURE 1 is a fragmentary View in side elevation taken on line 11 ofFIGURE 3, showing a device embodying the present invention;

FIGURE 2 is a view partly in elevation, partly brokenaway and partly insection, taken on line 22 near the left end of FIGURE 3;

FIGURE 3 is a top plan view of the device but with only the location ofcertain parts shown by dot-dash lines; and

FIGURE 4 is a side elevation of the same end of the.

device as shown in FIGURE 1, but taken from the right side of FIGURE 2.

Referring to these drawings, a frame is shown of heavy metalconstruction and having sides 10a and 10b, and extension 10c, and a pairof opposite, substantially parallel, longitudinally extending,substantially horizontal, stationary rest supports 11a and 11b locatedat the top of frame 10. Rest supports 11a and 11b may have rest saddlesor holding pins thereon for locating the articles accurately in place.

A first shaft 12 is rotatably mounted at the left end of FIGURES 1, 3and 4 substantially perpendicular to the stationary rest supports 11aand 11b in bearings 12a and 12b shown in FIGURE 3. A first sprocketwheel 13 of relatively large diameter is keyed on the right end of shaft12. A gear reducer 14 (see FIGURES 3 and 4) having an output shaft 15,with sprocket 17 keyed thereon and an input shaft 16, is positioned toalign the sprocket wheels 13 and 17, which are connected in tandem withsprocket chain 18.

An electric motor 19 is positioned beyond the gear reducer 14 and havinga drive pulley aligned with a pulley on the input shaft 16 and connectedby a V-belt 20. Overload protecting means 21 may be provided for theelectric motor 19, e.g., a slippable friction-type clutch, a shear pin,or other safety coupling, or a magnetic brake.

Turning now to the left end of FIGURE 1, a cam wheel 22 is fixedlyconnected to first shaft 12 to turn therewith. Cam wheel 22 provides alift period 23, a high-dwell period 24, a lowering period 25, and alowdwell period 26, assuming that it is rotating in a counterclockwisedirection. It is within the scope of the invention to have cam wheel 22rotate either way.

Near the top of FIGURE 2, a second shaft 27 substantially parallel tothe first shaft 12 is shown rotatably mounted in bearings 27a and 27bbetween the sides 10a and 10b of frame 10. A first lift arm 28a and asecond lift arm 28b are fixed (e.g., keyed, pinned or splined, etc.) onthe shaft 27 in spaced relation and substantially parallel to eachother. Flanged rollers 29a and 2% are connected to the free ends of liftarms 28a and 28b respectively and extend laterally therefrom.

A cam follower wheel 30 is pivotally mounted at an intermediate positionon the lift arm 28]; and extends laterally therefrom, to coact with camwheel 22.

It is within the scope of the invention to have a second carn wheel 22and a second cam follower 30 located to cooperate with lift arm 28a, inwhich case the arms 28a, 28b would not need to be keyed together. Thedistance from the first carn follower 30 to the second shaft 27determines the amplitude of upward swing of the cam followers at liftarms 28a and 28b, and therefore the lift of the rollers 29a and 29b. Thecloser cam follower 30 is to the second shaft 27, the greater the upwardswing, and, for a given arm length the greater the lift. The differencebetween radii of the rest period 26 and the high-dwell period 24 of camwheel 22, other things being constant, also determines the up wardswing, and the lift, of the lift arms 28.

A third shaft 31 is rotatably mounted in bearings 31a and 3112 (see theright end of FIGURE .3), respectively. on frame 10 and is substantiallyparallel to the shafts 12 and 27. Third and fourth lift arms 28c and 28dare fixedly connected to the third shaft 31 in spaced relationsubstantially parallel to each other and substantially parallel, and intandem with, the first and second lift arms 28a and 2812 respectively.Flanged rollers 29c and 1 29d are connected to the free ends of liftarms 28c and 28d respectively extending laterally therefrom in tandemwith the flanged rollers 29a and 2%, respectively, of first and secondlift arms 28a and 28b. It is within the scope of the invention to haveadditional lift arms.

Referring back to FIGURE 2, a pair of opposed substantially paralleltransfer bars 32a and 32b define the carrier or transverse member ofthis embodiment,'and each rides on the rollers 29a-d of lift arms 28a-d,respectively. These bars are adjacent to, and parallel to, the

' stationary rest supports 11a and 11b. Rollersj29ad have flanges 33a-drespectively which hold bars 32a and 32b thereon and preventlateraldisplacement. A series of cross bars 35 (FIGURE 2) rigidly interconnecttransfer bars 32a and 32b, and carry vertical cam bars 53. Transfer bars32 a and 32b may have rest supports, or saddles,

or holding pins for holding articles in place, not shown.

Shafts 27 and 31 extend laterally beyond the righthand side b of frame10, as shown in FIGURES 2 and 3. Shafts 27 and 31 have double yoke crankarms 36 and 37 respectively fixedly connected thereto and extendingupward therefrom. A connecting rod 34 is pivotally con nected betweenthe crank arms 36 and 37 to cause shafts 27 and 31 having lift arms28a-d to move in concert.

A stationary cam'38 is fixedly connected to frame 10, for example bywelding or bolting, as shown in the lefthand portion of FIGURE 2 and asbest seen at the lefthand portion of FIGURE 1. Stationary cam 38 hasflattened vertical edges 39 and 40 straight or described by arcs havingradii substantially larger than the radius of the circular. stationarycam 38, for reasons presently to be explained. It is within the scope ofthe invention to vary otherwise the shape of the circumference ofstationary cam 38. V

Referring to FIGURES l-3, a crank arm 41 is fixedly mounted on the endof shaft 12 just beyond the stationary cam 38 and substantially at themid-point of the low dwell 26 j of cam wheel 22. A lost'motionconnection 42, advantageously, as shown, an L-shaped clevis link, ispivotallyattached at one end of the arms 41. The outer end 42a of theL-shaped link 42, extends laterally therefrom and is positioned tofollow theperiphery of, and coact with, the stationary cam 38. A stoppin 45 is located on crank arm 41 so that end 42b of L-shaped link 42bears against it when cam follower 44 rides on the circular part 'ofstationary cam 38.

Referring now to FIGURE 2, a fourth shaft 46 is located at the bottom offrame 10 extending between the longitudinal frame members 10c and, 10dsubstantially parallel to first, second, and third shafts 12, 27 and 31respectively. Shaft 46 is located at the intermediate portion of frame10 as seen in FIGURE 1. A double lever 47 is rotatably mounted on shaft46 and a connecting rod 48 is pivotally connected to and betweenL-shaped link 42 and lever 47 at pins 49 and 50 respectively. The armsof lever 47 are designated 47a and 47b and are rigidly connected by astrut 47 c. The horizontal sweep of the free'end of lever 47 isdetermined by the location of pin 50'on lever 47. The closer the pin 50is to shaft 46, the greater the sweep. Adjustable stop bolts 51 and 52(FIGURE 1) are positioned to limit the to-and-fro movement of lever 47so that cam follower 44 does not move beyond the flattened vertical edgeportions 39 and respectively of stationary cam 38.

A vertical cam 53 is rigidly connected to transfer bars 7 32a and 32b asseen in FIGURE 2, and at an intermediate locationin FIGURE 1. As shown,cam 53 is indirectly mounted on bars 32a and 32b by a cross bar 35. Cam53 includes opposed depending vertical faces defining a channeltherebetween, closed by a stop located at the bottom end of cam.

The end' of lever 47 has a cam follower roller 57 which engages theopposed cam faces 53. Arms 47a and 47b straddle the cam 53.

Referring now to the right hand portion of FIGURE 2, a sprocket wheel 58is fixedly connected to first shaft 12 to rotate therewith. A timer 59is located in close proximity to sprocket wheel 58 with its own in-putsprocket wheel 61 connected thereto by drive chain 62. It is appreciatedthat other means may be used to actuate timer 59 This timer may be usedto energize and de-energize electrical devices at predetermined pointsin the transfer cycle, e.g., solenoid valves for washing jets, etc., tosynchronize in the cycle. 7 r

In operation, the rotation of cam wheel 22 in FIGURE 1 and coaction ofcam follower 30 cause lift arm 28b to swingupward and downward. Sincelift arm 28a is fixedly connected to the second shaft 27, which alsocarries lift arm 28b, these move inconcert; and, since shaft 27 isconnected to shaft 31 through the interaction of connecting rod 34 (asseen in the upper right-hand portion of FIGURE 2 and lower portion ofFIGURE 3). Lift arms 28c and 28d, fixed on shaft 31, also move inconcert with lift arm 28b. Lift arms 28ad elevate and lower transferbars 32a and 32b to lift an article off, or lower an article onto,stationary rest supports 11a and 11b.

Horizontal transference to different positions on stationary restsupports 11a and 11b is accomplished by the to-and-fro movement of lever47, as seen in FIGURE 1. Cam driver 57 rolls along (or within the broadterminology of the claim language slides) in the vertical channel of cam53 and thus converts the sinusoidal motion of roller 57 to purelyhorizontal motion as applied to the transfer bars 32. Cam 53, however,permits vertical motion of transfer bars 32a and 32b, although it doesnot transmit it. It is permissible within the broad scope of theinvention to modify the contour of channel 55 for special effects, e.g.,according to the specific inventions of one of us and our co-workers asdescribed in copending applications. It should be further noted thatlever 47 and connecting rod 48 are in effect a motion multiplier forincreasing the horizontal throw of crank arm 41. When the horizontalthrow of crank arm 41 alone is sufiicient, this invention can beeffectively practiced by having roller 44 bear directly on surface 53. VRectilinear motion of transfer bars 32a and 32b with sharp change fromlongitudinal to vertical and vice versa is accomplished by means ofstationary cam 38. When cam follower 44 is on the flattened verticaldwell 39 or 40 of stationary cam 38, is when the vertical motion oftransfer bars 32a and 32b should be the greatest, for the cam follower30 is on its lift period 23 or the lowering period 25 of cam wheel 22.The cam follower 44 proceeds along the dwell 39 while cam follower 30 islifted by cam 22. The horizontal component of the motion of lever 47 andconnecting rod, meanwhile, is negligible or completely arrested,depending on the exact shape of the flattened portion 39 on cam 38; thisoccurring preferably while vertical motion is being generated by the camfollower 30 riding along the lift period 23 of cam 22. Contouringstationary cam 38 with flattened vertical edges 39 and 40 thus reduceshorizontal motion while vertical motion is occurring, and thus providesclose to perfect rectilinear motion of the transfer bars 32a and 32b. Bygiving the flattened dwells a slight arc, concave at 40 and convex at 39with radiusequal to the length of 48 between pivots, all horizontalmotion will cease to be generated; and if the vertical motion generatedby cam 32 is properly timed, then exact rectilinear motion results.

L-shaped link 42 holds cam follower 44 against the circular portion ofthe circumference of stationary cam 38 by its end 42b bearing againststop pin 45. When the cam follower 44 reaches one of the flattenedportions 39 or 40 of stationary cam 38, adjustable stop bolts 51 and 52hold the cam follower 44 against the flat on cam 38, while thelost-motion link 42 accommodates the arcuate motion of the crank 41. Atthese times, end 42b of link 42 swings away fromstoppin 45. In theparticular example illustrated, the angle that lever 47 can move betweenstop bolts 51 and 52 has been arbitrarily set at 8530. It is, of course,within the scope of the invention to vary the angle according to thedesired throw of the bars 32.

. Other lost-motion links can be used instead of the L- shaped pivotedlink shown. Two requirements for such other lost-motion" linking means,which from this disclosure would be evident to a mechanic skilled in theart, are (l) to have means for keeping roller 44 engaged on theperipheral surface of cam 38 (e.g. spring loading the for the operationsbeing performed. The stopping device used for this function may also beenergized by an overload relief device, e.g., centrifugal switch 65, tostop, the operation until restarted by the operator after the abnormalcondition, such as the overload, is corrected.

It must be appreciated that in practice the transfer may be of a singlearticle or a series of articles which can be accommodated in a number-ofstations, respectively, in the length provided for by the transferdevice. The transfer device provided by this invention isolates insuccessive periods vertical motion and horizontal motion and providesfor acceleration of articles in each direction and for decelerationbefore setting them down again at another station.

Although the invention has been described with some particularity, it isto be understood that the particular embodiment shown and the variationsdescribed have been given by way of example, and numerous changes in thedetails of construction and the combination and arrangement of parts maybe resorted to without departing from the spirit and scope of theinvention.

We claim:

1. A transfer device adapted to transfer a plurality of articles insuccession from station to station along a path, which comprises spacedstationary rest supports, a pair of liftable and longitudinally slidabletransfer bars connected to said rest supports, rotary cam means coactingwith said transfer bars to impart vertical motion thereto, rotatingdrive means for said cam means, a lever pivotally anchored relative tosaid rest supports and slidably engagmg a bearing surface transverse to,and connected to, said transfer bars, a crank arm means operativelyconnecting said crank arm to said rotating drive means, a stationary camcoaxial with said crank arm and having substantially flattened oppositefaces, a connecting link including a lost-motion connection between saidcrank arm and said lever, and a cam follower coacting with saidstationary cam to activate said lost-motion connection at positionscorresponding to said flattened faces and thereby avoid impartinglongitudinal motion to said transfer bars at such position.

2. A transfer device adapted to elevate a first article from a firststation, to move the article along a path towards a second station, tolower the article into the second station, and to successively repeatthe above cycle with succeeding articles, which comprises a frame havinglaterally spaced substantially parallel longitudinally extendingstationary rest supports at the top thereof; a shaft rotatably mountedon said frame substantially perpendicular to the longitudinaldirectionof the stationary rest supports; drive means for said shaft; a cam wheelconnected to said shaft to turn therewith having a lift period, ahigh-dwell period, a lowering period, and a low-dwell period; a pair oflift arms, each having one end pivotally connected to said frame atpoints respectively spaced longitudinally, and having their outer endsbeing positioned and adapted for substantially free sliding movement ona transfer bar hereinafter specified and one of said lift arms having acam follower positioned to coact with said cam wheel; another pair oflift arms pivotally connected to said frame in laterally spacedrelationship to said first named pair and in tandem with, andsubstantially parallel to, each other and their outer ends beingpositioned and adapted for substantially free sliding movement on saidtransfer bars; a first transfer bar slidably supported on one pair ofarms; a second transfer bar slidably supported on the other pair of armsand connected to, and substantially parallel to, said first-namedtransfer bar; a stationary cam fixedly connected to said frame coaxialwith said shaft and having flattened sectors on opposite edges; a crankarm fixedly connected to said shaft to rotate therewith adiacent to saidstationary cam and positioned to substantially bisect one of the dwellsof said cam wheel; a lost-motion pivotal connection on said crank armradially spaced from said shaft; a lever pivotally connected to saidframe to swing on an arc with a horizontal cor ponent; a connecting rodpivotally connected between said lever and said lost-motion connection;a cam follower connected to said crank through said lost-motionconnection and extending laterally over the edge of, and positioned tocoact with, said stationary cam; a slotted member fixedly andtransversely attached to one of said transfer bars; and a drive bearingconnected to said lever, extending into, and substantially fitting, thelateral slot thereof and positioned to coact with said slotted member todrive the transfer bar longitudinally when the lever is swung.

3. A transfer device adapted to elevate a first article from a firststation, to move the article along a path towards a second station, thento lower the article into the second station, and to successively repeatthe above cycle with succeeding articles, which comprises a frame havingrest supports at the top thereof; a cam and means for driving it, saidcam having a lift period, a highdwell period, a lowering period, and alow-dwell period; lift arms, each pivotally connected to the frame andan end of each being adapted to slide on a transfer bar hereinaftermentioned, and one of said lift arms having a cam follower connectedthereto and positioned to coact with said cam, at least two of said liftarms being spaced longitudinally, and means pivotally connected to both,tying them together at the same radii from the axes of their respectivepivot connections to the frame and at the same distance apart as thatbetween the axes of said pivotal connections whereby said arms operatein tandem with, and always substantially parallel to, each other; acarrier transfer bar slidably supported on the lift arms, asubstantially circular stationary cam fixedly connected to said framecoaxial with said driven cam and, having flattened opposite edgesdescribed by arcs having radii substantially longer than the radius ofsaid circular stationary cam; a crank arm mounted to rotate adjacent andcoaxial with said stationary cam and substantially to bisect thehigh-dwell and low-dwell periods of said driven cam; an L-shaped linkhaving one end pivotally, connected to the outer end of said crank arm;a lever pivotally connected to the frame; a connecting rod having oneend pivotally connected between said link and said lever at asubstantial radius from its connection on the frame; a cam follower onsaid link positioned to coact with said stationary cam; a verticallyslotted member fixed on and depending from one of said transfer bar; andslide means on said lever, extending into said slot to coact with saidvertical guide.

4. A transfer device as defined in claim 3 inwhich at least one of theflattened portions of the stationary cam are arcuate with substantiallygreater radius than the radius of the intermediate portions of the cam.

5. A transfer device adapted to transfer a plurality of articles insuccession from station to station along a path compiising a pair ofopposed substantially parallel longitudinally extending substantiallyhorizontal stationary rest supports, each having a first end, a secondend, and an intermediate portion; a shaft rotatably mounted at the firstends of said rest supports substantially perpendicular thereto; rotatingmeans for said shaft; a cam wheel on said shaft connected to turntherewith having a lift period, a high-dwell period, a lower ing period,and a low-dwell period, a plurality of lift arms of substantially equallength, one end of each being pivotally connected to said rest supportsand one of said lift arms having a cam follower roller extendinglaterally therefrom positioned to coact with said cam wheel; a pair ofopposed substantially parallel transfer bars, slidably carried on thesecond ends of said lift arms, whereby they are kept substantiallyparallel to said rest supports; a stationary cam fixedly connected tosaid frame coaxial with said shaft and having flattened oppositevertical edges; a crank arm fixedly connected coaxial to said shaft, torotate therewith, and adjacent said stationary cam substantiallybisecting the high and low dwells of said cam wheel; stop means at aninter- 'mediate portion of said crank arm extending laterally therefrom;an L-shaped link with its intermediate portion pivotally connected tothe outer end of said crank arm and the foot of its L positioned to bearagainst said stop means; a lever pivotally mounted and connected to theintermediate portion of said stationary rest supports; adjustable stopmeans to limit to desired amplitude the to-and-fro movement of saidlever and thereby the longitudinal transfer of said articles; aconnecting rod having the one end pivotally connected to theintermediate portion of said lever and the outer end pivotally connectedto the outer end of said L-shaped link; a cam follower connected to theouter end of said L-shaped link, extending laterally therefrom over saidstationary cam to coact therewith; a vertical bearing surface fixedlyprotective from the transfer bars; and a cam driver connected to theouter end of said lever, extending laterally therefrom, and positionedto coact with said vertical bearing face.

6. A device as described in claim which further includes a timer fortiming the idle periods of said electric motor to correspond withperiods of desired operations at said stations.

7. A transfer device adapted to transfer at least one article fromstation to station along a predetermined path, which comprises a machineframe; a transfer member; rotary drive means; means for converting saidrotary drive to individually controlled reciprocating vertical motion;means for converting the rotary drive to individually controlledreciprocating horizontal motion including a crank arm rotatably mountedon said machine frame and operatively connected to said rotary drivemeans, a stationary substantially circular cam having substantiallyflattened opposing peripheral dwell faces, said stationary cam beingfixed to said machine frame coaxial with said crank arm, avertical-lost-motion means for imparting only the horizontal componentof motion derived from said rotary drive means through said crank arm,this vertical-lost-motion means defining a vertical channel andincluding an anti-friction driver riding in said channel, and connectingmeans extending between said crank arm and said anti-friction driver forimparting at least a substantial portion of the horizontal motiongenerated by said crank arm to said driver, said connecting means beingpivotally attached to the free end of said crank arm and including alost-motion linking means adapted to follow the periphery of saidstationary cam thereby at least substantially interrupting thehorizontal motion conveyed there- 8 between when saidlost-motion-linking means transverses the dwellfaces of said stationarycam.

8.. A transfer device as defined in claim 7 wherein the 'dwell faces ofsaid stationary cam are vertically flat throughout at least asubstantial portion of each dwell 'face.

9. A device as described in claim 7 wherein the two oppositely disposeddwell faces of the stationary cam are flattened to accommodate apredetermined portion of the horizontal motion generated by said crankarm.

10. A transfer device adapted to transfer at least one article fromstation to station along a predetermined path, 'which comprises amachine frame; a transfer member; rotary drive means; means forconverting said rotary drive to individually controlled reciprocatingvertical'motion; means for converting the rotary drive to individuallycontrolled reciprocating horizontal motion including a crank 'armrotatably mounted on said machine frame and operatively connected tosaid rotary drive means, a stationary substantially circular cam havingsusbtantially flattened opposing peripheral dwell faces, said cam beingfixed to said machine frame coaxial with said crank arm, a verticallyslotted member fixed to and depending from said transfer member, a leverpivotally anchored to said machine frame and slidably engaged at itsfree end in said vertically slotted member, a connecting rod extendingbetween said crank arm and said lever and being pivotally connected atone end to an intermediate portion of said lever, and a lost-motionlinking means connecting said other end of said rod with the free end ofsaid crank arm and including a cam follower mounted on said other end ofsaid connecting rod, which cam follower coacts with the peripheralsurfaces of said stationary cam to activate this lost-motion linkingmeans while it traverses said dwell faces thereby absorbing apredetermined portion of the horizontal motion being conveyed to saidtransfer member.

11. A device as described in claim 10 where said 10stmotion linkingmeans comprises an L-shaped link pivotally connected at one arm to saidconnecting rod, a stop mounted on said crank arm to engage the inside ofthe other arm of said L-shaped link to prevent said cam follower fromdisengaging the circular portionsof the stationary cam.

12. A device as described in claim 11 further including stop means fordelimiting the maximum arc of said lever.

References Cited in the file of this patent UNITED STATES PATENTS1,000,828 Lorillard Aug. 15, 1911

1. A TRANSFER DEVICE ADAPTED TO TRANSFER A PLURALITY OF ARTICLES INSUCCESSION FROM STATION TO STATION ALONG A PATH, WHICH COMPRISES SPACEDSTATIONARY REST SUPPORTS, A PAIR OF LIFTABLE AND LONGITUDINALLY SLIDABLETRANSFER BARS CONNECTED TO SAID REST SUPPORTS, ROTARY CAM MEANS COACTINGWITH SAID TRANSFER BARS TO IMPART VERTICAL MOTION THERETO, ROTATINGDRIVE MEANS FOR SAID CAM MEANS, A LEVER PIVOTALLY ANCHORED RELATIVE TOSAID REST SUPPORTS AND SLIDABLY ENGAGING A BEARING SURFACE TRANSVERSETO, AND CONNECTED TO, SAID TRANSFER BARS, A CRANK ARM MEANS OPERATIVELYCONNECTING SAID CRANK ARM TO SAID ROTATING DRIVE MEANS, A